Seals are used in a number of applications to provide a sealing function between two moving parts. For example, a piston arrangement may include a piston that is movable within a cylinder. The piston will function to separate two chambers, wherein the volume of each chamber varies depending on the position of the piston. Typically the piston and cylinder are metallic and a seal must be provided between these two components to prevent their contact whilst sealing the chambers, so as to prevent substantial amounts of fluid transferring from one chamber to the other.
The health monitoring of such seals may carried out conventionally by replacing the seals well before the end of their potential service life. This has been done to ensure that they do not catastrophically fail suddenly during use. Methods are known for monitoring actuator health, but these typically involve manual inspection and/or are only able to detect the health of the actuator as a whole, and cannot specifically detect the health or failure of the seal that is located on the actuator piston.
It is desired to provide an improved method for monitoring the health of a seal located on an actuator piston, that is able to provide an improved indication regarding its health.